Compositions and methods for making livestock with a polled allele are presented, including migrating a polled allele into a bovine species without changing other genes or chromosomal portions. Animals may be genetically modified so that they do not have horns. One such process involves introgression of the bovine polled allele. A livestock breed is thus made to receive the polled allele without change to their other traits. An embodiment of the invention is a genetically modified livestock animal comprising a genomic odification from a homed allele to a polled allele.
